Why people in one county live 18 years longer than those in another county nearby

Ellie KincaidApr 15, 2015, 01:25 IST

REUTERS/ Finbarr O'Reilly

Only 350 miles separate Fairfax County, Virginia, and McDowell County, West Virginia, geographically. But if you look at the average life expectancy in each community, they look like they're on different continents.

The average life expectancy in Fairfax County, 82 years for men and 85 for women, is comparable to what it would be in Sweden. In McDowell County, on the other hand, life expectancy is 64 years for men and 73 for women, more like the average for Iraq.

That huge disparity in life expectancy coincides with another significant difference between the counties: income.

The median household income in Fairfax County is $111,079, with 34.5% of households earning more than $150,000, according to stats on the county's website from the US Census Bureau. Census data for McDowell County are very different. Thirty-six percent of McDowell County's residents are below the federal poverty level, and the median household income is only $22,252.

Granted, the counties differ in many other significant ways, and that 350 miles makes a world of difference. Fairfax County is located in the suburbs of Washington, D.C., and is densely populated, with 2,744 people per square mile. McDowell County, in rural Appalachia, has a population density of only 41.5 people per square mile. McDowell County also has a much smaller percentage of residents with at least a Bachelor's degree, 5.8% of people over 25 to Fairfax County's 60%.

Other differences between the two counties make it complicated to say income is for sure the sole or even biggest reason life expectancy differs so much between Fairfax County and McDowell County. But it's likely a crucial factor. The US National Center for Health Statistics calls the association between health and socioeconomic factors such as income and education "well established."

The income-health connection

Comparing life expectancies of Americans at opposite ends of the wealth spectrum, as The New York Times did in 2014, provides an extreme case that income and health are intertwined. But yourincome affects your health no matter how much money you make, said Laudan Aron of the Urban Institute, a nonpartisan think tank.

Aron is a coauthor of a report from the Urban Institute and Virginia Commonwealth University that traces some of the links between income and health that contribute to the "longevity gap."

"Wherever you are [in terms of income], people much better off than you are going to be healthier and live longer, and people that are less well off financially are probably, as a group, on average, not going to live as long and be less healthy," Aron told Business Insider.

The graph below shows that as family income (measured in relation to the Federal Poverty Level - $24,250 for a family of four in 2015) increases, the number of years an adult can expect to live increases as well. If your family income is two times the Federal Poverty Level, you get on average two more years of life than someone whose family income is less than the Federal Poverty Level, and on up the scale. It seems money can buy you more time alive.

Urban Institute, Virginia Commonwealth University

What's going on?

Length of life isn't the only thing that changes with income level.

In their report, Aron and her colleagues cite data from the Centers for Disease Control and Prevention showing that certain diseases are less widespread among higher-income groups. Coronary heart disease, stroke, diabetes, arthritis, and many other health problems affect smaller and smaller chunks of the population in each increasing income bracket.

For example, strokes affect 3.9% of people with family incomes less than $35,000, 2.5% of people in families earning between $35,000 and $50,000, 2.3% of people in the $50,000 to $75,000 group, 1.8% of people making $75,000 to $100,000, and 1.6% of people whose families earn more than $100,000. The more money you make, the less likely you are to have a stroke, according to the data.

Increased disease incidence with decreasing income is only part of the story. The graph below shows that as income goes up, fewer people say they have fair or poor health. While 22.8% of people in households earning less than $35,000 say they are in "fair or poor health," only 5.6% of people in households earning $100,000 or more say the same.

Urban Institute, Virginia Commonwealth University

In their report, Aron and her colleagues aim to tease out how income affects people's health, keeping in mind that health also influences income (someone with poor health will have a harder time working).

Still, the brief identifies a few explicit ways income affects health:

People with lower incomes typically have less money to spend taking care of themselves, whether paying for visits to the doctor, medicine, or healthy food.

People with higher incomes live in areas with healthier resources available, like good grocery stores, safe housing, opportunities to exercise, clean air, and better schools.

These bullet points dramatically simplify the numerous and complicated ways income affects health, and it's important to note that every individual will experience different pressures in various degrees.

The researchers acknowledge that poor health and disabilities can get in the way of people earning more money, making it difficult to say whether in any given scenario low income causes poor health or vice versa. All the relationships between health and income are very complex and hard to study, but there's no question that there's a strong connection between low income and poor health.

Now what?

The researchers point out that public policies primarily considered for their economic impact have consequences for health, too.

"Because of how we've organized our society, and the nature of the safety net in this country relative to some other high income countries, lower income Americans are especially vulnerable to poor health," Aron told Business Insider.

For example, the researchers cited a study comparing mortality in unemployed Americans and Germans. The paper, published in the American Journal of Public Health, found unemployed Americans were more likely to die than working Americans, but Germans were no less likely to die if they were unemployed.

Aron hopes the report will encourage policymakers to consider health effects in discussions about economic problems and initiatives.

Conversations about employment and training programs, for example, "are as much about health as about economic self sufficiency," Aron said. "We're trying to show they're actually very intimately linked."